CONAKRY, Guinea — Officials say 12 people were killed and 50 injured in ethnic violence in the West African nation of Guinea, leading the army to impose a curfew in the country's second-largest city.

Army Capt. Pepe Koivogui said Tuesday a curfew would restore calm.

The violence began Monday in the village of Koule, more than 800 kilometers (497 miles) southeast of the capital, Conakry. It was sparked when members of the local Guerze ethnic group beat a young Konianke man to death after accusing him of stealing from a gas station.

Hospital official Alpha Saliou Sow said 11 more people were killed by Tuesday afternoon in the nearby city of N'Zerekore.

Guinea is preparing for legislative elections in September that analysts warn could be marred by ethnic violence.